Incandescent mantle.



magma Sv. GULBRANDSEN. INANDESGENT MANTLE. APPLICATION FILED MAY e,1914.

SVERl'tE GULENDSN, GF YOODBU JERSEY, ASSIGNOR TO WELSBACH LIGHTCQLCEFANY, 0F GLOUESTER CITY, NEW JERSEY, A CGRORATIN OF NEW JERSEY.

moaitnnscnnr MANTLE.

- application inea may 6,1914.. sans] un. aan@ Beit known that ll,SVBRRE. a citizen ofthe United States, "residing at lVoodbury, in thecounty'ofGloucester and 4'State of New Jersey, have invented. a new 2'is a similar View sliowingthe mantle after shaping in actual burninguse,"

My invention relates -to inverted'incan'descentmantlesof the limp 'orrag type; and is designed to' provide a :mantle of'this type which willgive 'a superior light and which will shape itself under vburning inactual use on ordinary city gas pressures.' On ordinary-city pressures,fa closed 4top mantle off the usual size v(f'romonei and one-'eighthinches to' one and three-eighths inches in diameter) ygives .very 4little incandescence.

and therefore very little light; j Furthermore, 'it presents acharacteristicappearance in that it-has a heavy and `local llame sur#V yrounding it and 'extending .to a distanceof approximatelya quarter-0f aninch from-the exterior surface of the mantle. Attempts to bring theflame nearer tof'thev mantle surf tace byl cutting doiiyiifthegasslipply'at the orifice oftlieburner are unsuccessful, as

such attempts'cause'aneven further dulling ofthe light. In fact, thereisnol adjustment I. i possible by which the flame V'can be concen-itrated,in such mantle at the mantle surface,

since the supply ofga's necessary'for heating the mantlewill be toogreat for the air entrained .to form perfect combustion and if the gas'supply is reduced to form the proper mixture with the air entrainedinthe sup-,

ply of .fuel is too small to heatl the mantle up to the properincandescence. The action of 'a closed top mantle of the` usual size, asabove described,A With ordinarycity 'gas 'pres-1 sures, is dueto'the'fol'lowing facts. y The air (primary air) entrained by the' gasstream is very considerably less than thatrequired' for the completecombustion ofthe gas. The balance of the air (se'condaryair) istherefore taken' from around thefmaiitle.

This means that all the gas has to -pass themeshes of the mantle andtravelthrough Specification of Letters Fatent.

GULBPei NDsnN,

Patented irais so, rais.

L ,i some distance fromv the surface thereof before it finds sulicientair for complete combustion: This'causes the heat of the iianie to hedissipated intospace instead of being made effective at themantle-surface. With an opent-top shaped mantle of the usual size, thisthiiiculty is not present because some of thc products vof combustionfind a vent,

through the space'b'etween the mantle ring and the burner tip, 'thusestablishing a sort of chimney effect vwhich allows the secondary air tosweep closer to the mantle. This brings the zone of combustion nearer tothe mantle surface-and increases the incaudes- Vthat the llame will belocated close to the.

mantle surface; and that such mantle Will also properlyshape itself iiithe burning op-l eration.` Theactioii of such a mantle is in factradically different from the action of a sin'iilariiiantle of the usualsize. This is due to the fact that as the size of the mantle -isldecreased beyondv a certain point its surface `becomes much llarger 'incomparison with its lvolume or llame capacity. In such a mantletherefore it becomes possible for the ygasto' obtain a sufficient supplyof -sec- -ondary air" much closer to the mantle' surface.' lThe vamount.of gasjrequiied being ijelatively'small this Will entrain more nearlytlie' 'pr0p'er proportion of primary air, and moreover the requiredsupply' of this sec. ondary airis much less. There is another importantfactor which also enters into this result. In every mantle a certainamount of combustion takes place on `the inside of the mantlebeti'veenthe gas and. the primary air. l'iiano'pen Bunseii flame tliiscomhusytion takes place at the inner cone of the fia-me,^irhicli, as is known,vis itshotte'st part. 'inthe small mantle produced by my invention thisprimaryconibustion is caused to take `place very 'considerably-closer tothe vmantle surface .than is the vcase in va large mantle. The proximity-of this Very hot 'zone' to the mantle Walls. produces 'a higherincandescence. The d ifliculties Iheretofore experienced with large sizerag mantleslwith closed tops, 4When'fiised with ordinary. city fgaspressures liavelimited their use to sysi oo satisfactory shape; and ifclosed at thetopv they would not give a satisfactory light for thereasons above stated.

My invention is based upon the discovery that the liame capacity of arag mantle must bear a certain relation to its surface area; and thatwhen the diameter of the mantle `does not exceed seven-eighths of aninch, when shaped, the mantle hasa flame capacity which bears such arelation to its surface area that the desired eliiciency, tovether withproper shaping, may be obtained with A ordinary city gas pressures.

Another way of defining my im roved mantle is that the ratio of thesurface in .square inches to the volume i'n cubic inches 1s not lessthan five; that 1s, its surface'in` square inches is not less than livetimes its volume in cubic inches. (These measurements refer to thenished shaped mantle.) Of course, the volume-capacityof a mantleincreases much more rapidly than its area with increasing diameters, andI have found that it is for this reason that the mantle must be vbelow acertain diameter when shaped, in order to give the proper results andallow shaping in place under burning conditions. v

In the drawings, 2 represents a limp or rag mantle having its mouthtied, or otherwise secured within the annular recess of a metal carrier3. This metal carrier in the form shown has an internal screw-threadedstem which is'adapted to screw on the correspondingly threaded tip of aninverted incandescent burner.

In using these small mantles, they are simply screwed in place lon theinv rted burners and the organic fabnic burne off with a match or taper;the mixture of gas and air is then turned on and ignited, the

i mantles then shaping into approximately the form shown at 2 in Fig. 2,under prdinary shape are obtained by using mantles which, when shaped,have a diameter of from ve-eighths to one-half of Aan inch, andseven-eighths of ity vgas pressures. The mantles thus l -are good inappearance land give good efliciency in burning. .Thebest results aninch to one inch is the outside limit which can be used 1n this manner.I also preier to use mantles which are not less than one- Afourth of aninch in diameter when burned and shaped.

The advantages of my invention will be obvious to those skilled in theart. The expense and delay incident to burning, shap- 1 ing, hardeningand collodionizing in the facn ture, and in the small diameter themantles in connection with the closed end will properly shape underordinary gas pressures, they present a decided advance in this art andwiden the field available for inverted incandescent mantles.

nection to burners using ordinary gas pres.

sures, and a carrier having a coi-responds ingly reduced opening towhich the open end of the mantle is secured, substantially asvdescribed.

2. As a new article of manufacture, a limp mantle reduced in'size toless than one inch diameter when shaped, and adapted for con- 'nectionto burners using ordinary gas pres- \duced limp mantle adapted forconnection to burners using ordinary city gas pressures,

said mantle having its surface area less than five times its volume whenshaped, and its open end portion adapted to be tightly se cured to areduced burner tip, substantially as described.

In testimony whereof, I have hereunto set my hand.

SVERRE GULBRANDSEN.

VVitnesses-i J. I-I. JOHNSON, L. H. BoRNHorF.

Copies ofr this patent may be obtained` torve cents each, by addressingthe Commissioner nf Patents 'ilashing'toml D. C.

